Opera Gallery celebrates its 25th anniversary as one the leading dealers of contemporary art at this year’s Masterpiece London event, taking place from 27th June to 3rd July in Chelsea, London. The gallery will present an impressive selection of contemporary art by some of the most established artists of the 20th century, including Marc Chagall, Alexander Calder and Henri Matisse. Two previously unseen works by the iconic American painter Keith Haring will also be for...